316 GEOL. AND NAT. HIST. RUEVEY OF MINNESOTA. 



Erpetocypris barbatiis (Forbes.) 



Plate LXXVII. 



1879.— Candona omnia (?) C. L. Herrick (83), p. 113; PI. XX, Fig. 1. 

 ISd^.—Cyprisharbatm S. A. Forbes (67a), pp. 214-246; PI. XXXVII, Figs. 2 3; PL 

 XXXVIII. 



This, which is probably the largest freshwater ostracode, is known 

 to me only through the paper of Professor S. A. Forbes. The follow- 

 ing description, as well as the figures, is copied from his paper. 



"An extremely large, very hairy, oblong Cypris, with rounded ends 

 and dorsal and ventral margins nearly parallel. Length 4.0 mm. 

 Width 1.6 mm. Depth 2.0 mm. A very little deepest at hind end 

 of hinge margin. (Depth across eye 95 per cent of greatest depth.) 



''Dorsal margin about straight for a great part of its length, the 

 ventral margin very slightly emarginate or sinuate at its anterior 

 third. The anterior end broadly and smoothly rounded, more 

 obliquely above than below, the posterior somewhat obliquely 

 rounded, the ventral margin being thus nearly half as long again as 

 the dorsal. Seen from above the shape is symmetrical, a slender oval^ 

 a little more flattened at the sides behind than before; thickest, con- 

 sequently, before the middle. 



"Color a dirty yellowish brown in alcohol, with a reddish-brown 

 patch on either side above and behind the middle. Surface of valves 

 opaque, very minutely roughened, and well covered with conspicuous 

 hairs, which give this Cypris \^I'2rpetociipris] a decidedly hairy appear- 

 ance to the naked eye. Hairs longest before and behind and length- 

 ening generally towards the margin, where they project as a fringe^ 

 the most prominent part of which is a row of hairs borne on slender 

 conical tubercles within the margin of the valves. The valves are 

 equal and the shell fairly full, but not plump. 



"Anterior antenna with the basal segment obliquely channeled,, 

 partially dividing it into two, the distal part of which bears a single 

 bristle on its superior surface, and two long, more slender ones, 

 springing together from tip of the ventral surface. A short, subquad- 

 rate second segment bears a single seta, about as long as the segment, 

 on the dorsal surface, near the tip. From the distal end of the fol- 

 lowing segment spring two long, slightly plumose setse, one dorsal,, 

 one ventral, the former much the longer. The fourth segment bears 

 at its tip four long setse, two of which arise from the ventral angle and 

 two from the outer dorsal. The following segment is similarly armed, 

 and the distal extremities of the sixth and seventh are densely set 

 with long plumose setee forming a stout fascicle, which extends beyond 

 the end of the antenna a disfeance equal to the length of the antenna 

 itself. 



